IBM Corporation's TCMs (temperature controlled modules) provide a very high circuit packing density. These TCMs can hold for example over 150 integrated circuit chips and the number of chips is increasing. The TCMs are then placed on a mother circuit board sometimes referred to as "Clark" board that provides a relatively high circuit density. When these Clark boards are placed in a standard frame which is 749.3 millimeters wide, 1705 millimeters high and about 1524 millimeters long along with the power supply, it is only possible to place two such Clark boards in a frame with a board TCM density of only six 127 millimeter TCMs. This only packages 12 TCMs to a frame. The power supplies are separately located in the frame and heavy bus lines are used to connect the TCMs to the power supplies.